Let me first clarify that by fuel consumption, I mean the total energy use across all sectors, not just electricity generation. This distinction is important especially for oil, which is used primarily in transportation rather than in power generation. Also, when I use the term energy production, I actually mean energy conversion since energy cannot be created or destroyed, only transformed from one form to another. However, I’ll stick to the commonly (though technically incorrect) phrase energy production to keep the explanation simple.

According to the latest data, nearly 80% of all energy consumed worldwide still comes from non-renewable sources:

• Oil — 30%
• Coal — 25%
• Natural gas — 20%
• Nuclear fission — 5%

The remaining 20% comes from renewable energy sources, primarily hydropower, solar, wind, and bioenergy.

When we look at the long-term trends, coal consumption is decreasing sharply, oil is declining more gradually, and natural gas and nuclear power remain relatively stable. How these trends evolve will depend on many factors. One of the most important is the expansion of electricity generation in developing countries. Fossil fuels are technologically easy to use, and building a coal-fired power plant is far simpler than constructing a nuclear facility.

Hydropower plants, while technologically straightforward, require major infrastructure projects (the Three Gorges Dam in China, for example, took 20 years to build), as well as significant land use and water resources. Solar power plants are the easiest to install, but they have low power density, meaning they need large surface areas to generate substantial output.

The share of oil in total energy consumption is already declining, largely due to the rise of electric mobility. Natural gas, often used for heating, can increasingly be replaced by electricity, for example through heat pumps.

Because access to energy remains highly unequal across the globe, expanding energy production will be one of the key challenges in shaping the future energy mix. To illustrate: an average U.S. citizen consumes about 13 times more energy per year than an average Indian citizen. Given that India’s population is roughly four times larger than that of the U.S., equalizing per capita energy use would require 52 times more energy than we currently produce (4 × 13 = 52).